As a prior antenna apparatus attached to a vehicle, an antenna apparatus which can receive AM broadcast and FM broadcast is generally used. In this antenna apparatus, a rod antenna having a length of about 1 m is used to receive the AM broadcast and the FM broadcast. The length of the antenna is considerably short for a wavelength in an AM waveband although the wavelength is ¼ wavelength in an FM waveband. For this reason, the sensitivity of the antenna is especially deteriorated. Therefore, an impedance of the rod antenna is made high for the AM waveband, or an amplifier for the AM waveband is used to assure a high sensitivity. Furthermore, a vehicle antenna apparatus in which a helical antenna obtained by helically winding an antenna rod portion to shorten an antenna length to about 180 mm to 400 mm is also used. However, an amplifier is arranged immediately below the antenna to compensate for the deterioration of performance caused by the shortening of the rod portion.
A configuration in which a prior antenna apparatus 401 having a rod portion is attached to a vehicle 402 is shown in FIG. 41. As shown in FIG. 41, the prior antenna apparatus 401 is attached on the roof of the vehicle 402. A height h10 of the antenna apparatus 401 projecting from the vehicle 402 is set at about 200 mm. The rod portion of the antenna apparatus 401 is a helical antenna obtained by helically winding an antenna. Since the antenna apparatus 401 projects from the vehicle 402 as described above, the rod portion may collide to be broken in shedding or washing of the vehicle. Therefore, an antenna apparatus in which the rod portion of the antenna apparatus 401 can be bent along the roof of the vehicle 402 is also known.    [Patent Document 1] Japanese Publication Unexamined Patent Application No. 2005-223957    [Patent Document 2] Japanese Publication Unexamined Patent Application No. 2003-188619